kconfig: Sync with upstream v4.16

This commit introduces the following upstream changes:

5ae6fcc4bb82 kconfig: fix line number in recursive inclusion error message
1a90ce36c6ef kconfig: Update ncurses package names for menuconfig
bf0bbdcf1003 kconfig: Don't leak choice names during parsing
f4bc1eefc160 kconfig: set SYMBOL_AUTO to the symbol marked with defconfig_list
cd81fc82b93f kconfig: add xstrdup() helper
523ca58b7db2 kconfig: remove const qualifier from sym_expand_string_value()
d717f24d8c68 kconfig: add xrealloc() helper
9e3e10c72536 kconfig: send error messages to stderr
f3ff6fb5db68 kconfig: echo stdin to stdout if either is redirected
d2a04648a5db kconfig: remove check_stdin()
cd58a91def2a kconfig: remove 'config*' pattern from .gitignnore
4f208f392103 kconfig: show '?' prompt even if no help text is available
cb67ab2cd2b8 kconfig: do not write choice values when their dependency becomes n
1b9eda2e4892 kconfig: Warn if help text is blank
cedd55d49dee kconfig: Remove silentoldconfig from help and docs; fix kconfig/conf's help
1ccb27143360 kconfig: make "Selected by:" and "Implied by:" readable
312ee68752fa kconfig: announce removal of oldnoconfig if used
d0fd0428ecf0 kconfig: fix make xconfig when gettext is missing
b53688014e33 kconfig: Clarify menu and 'if' dependency propagation
9d1a9e8bc18b kconfig: Document 'if' flattening logic
d3465af60f44 kconfig: Clarify choice dependency propagation
3e41ba05b6d6 kconfig: Document SYMBOL_OPTIONAL logic
765f4cdef6f8 kconfig: use default 'yy' prefix for lexer and parser
84dd95d4f87a kconfig: make conf_unsaved a local variable of conf_read()
5a3dc717b3c7 kconfig: make xfgets() really static
52e58a3caeba kconfig: make input_mode static
6479f327dea6 kconfig: Warn if there is more than one help text
b92d804a5179 kconfig: drop 'boolean' keyword
df60f4b92d3d kconfig: Remove menu_end_entry()
0735f7e5def2 kconfig: Document important expression functions
05cccce58045 kconfig: Document automatic submenu creation code
7cf33f88e294 kconfig: Fix choice symbol expression leak
5b1374b3b3c2 kconfig: Fix expr_free() E_NOT leak
ae7440ef0c80 kconfig: Fix automatic menu creation mem leak
0724a7c32a54 kconfig: Don't leak main menus during parsing
bc28fe1d5ede kconfig: Don't leak 'option' arguments during parsing
24161a6711c9 kconfig: Don't leak 'source' filenames during parsing
26e47a3c11a2 kconfig: Don't leak symbol names during parsing
29c833061c1d kconfig: generate lexer and parser during build instead of shipping
e3b03bf29d6b kconfig: display recursive dependency resolution hint just once
f77850d3fe0c kconfig: Clean up modules handling and fix crash
fa8cedaef814 kconfig: Clarify expression rewriting
9a826842ff2f kconfig: Rename menu_check_dep() to rewrite_m()
c873443430eb kconfig: Sync zconf.y with zconf.tab.c_shipped
52aede4ba5ef kconfig: Document the 'symbol' struct
33ca1a248663 kconfig: Document the 'menu' struct
2c37e08464a8 kconfig: Warn if choice default is not in choice

Signed-off-by: Chris Packham <judge.packham@gmail.com>

1 files changed, 170 insertions, 17 deletions

diff --git a/kconfig/menu.c b/kconfig/menu.c
index 1fd7b25..d5a3322 100644
--- a/kconfig/menu.c
+++ b/kconfig/menu.c
@@ -62,13 +62,8 @@ void menu_add_entry(struct symbol *sym)
 		menu_add_symbol(P_SYMBOL, sym, NULL);
 }
 
-void menu_end_entry(void)
-{
-}
-
 struct menu *menu_add_menu(void)
 {
-	menu_end_entry();
 	last_entry_ptr = &current_entry->list;
 	return current_menu = current_entry;
 }
@@ -79,19 +74,23 @@ void menu_end_menu(void)
 	current_menu = current_menu->parent;
 }
 
-static struct expr *menu_check_dep(struct expr *e)
+/*
+ * Rewrites 'm' to 'm' && MODULES, so that it evaluates to 'n' when running
+ * without modules
+ */
+static struct expr *rewrite_m(struct expr *e)
 {
 	if (!e)
 		return e;
 
 	switch (e->type) {
 	case E_NOT:
-		e->left.expr = menu_check_dep(e->left.expr);
+		e->left.expr = rewrite_m(e->left.expr);
 		break;
 	case E_OR:
 	case E_AND:
-		e->left.expr = menu_check_dep(e->left.expr);
-		e->right.expr = menu_check_dep(e->right.expr);
+		e->left.expr = rewrite_m(e->left.expr);
+		e->right.expr = rewrite_m(e->right.expr);
 		break;
 	case E_SYMBOL:
 		/* change 'm' into 'm' && MODULES */
@@ -106,7 +105,7 @@ static struct expr *menu_check_dep(struct expr *e)
 
 void menu_add_dep(struct expr *dep)
 {
-	current_entry->dep = expr_alloc_and(current_entry->dep, menu_check_dep(dep));
+	current_entry->dep = expr_alloc_and(current_entry->dep, dep);
 }
 
 void menu_set_type(int type)
@@ -131,7 +130,7 @@ static struct property *menu_add_prop(enum prop_type type, char *prompt, struct
 
 	prop->menu = current_entry;
 	prop->expr = expr;
-	prop->visible.expr = menu_check_dep(dep);
+	prop->visible.expr = dep;
 
 	if (prompt) {
 		/* For crostool-NG, a leading pipe followed with spaces
@@ -219,6 +218,7 @@ void menu_add_option(int token, char *arg)
 			sym_defconfig_list = current_entry->sym;
 		else if (sym_defconfig_list != current_entry->sym)
 			zconf_error("trying to redefine defconfig symbol");
+		sym_defconfig_list->flags |= SYMBOL_AUTO;
 		break;
 	case T_OPT_ENV:
 		prop_add_env(arg);
@@ -258,6 +258,16 @@ static void sym_check_prop(struct symbol *sym)
 					    "'%s': number is invalid",
 					    sym->name);
 			}
+			if (sym_is_choice(sym)) {
+				struct property *choice_prop =
+					sym_get_choice_prop(sym2);
+
+				if (!choice_prop ||
+				    prop_get_symbol(choice_prop) != sym)
+					prop_warn(prop,
+						  "choice default symbol '%s' is not contained in the choice",
+						  sym2->name);
+			}
 			break;
 		case P_SELECT:
 		case P_IMPLY:
@@ -266,13 +276,13 @@ static void sym_check_prop(struct symbol *sym)
 			if (sym->type != S_BOOLEAN && sym->type != S_TRISTATE)
 				prop_warn(prop,
 				    "config symbol '%s' uses %s, but is "
-				    "not boolean or tristate", sym->name, use);
+				    "not bool or tristate", sym->name, use);
 			else if (sym2->type != S_UNKNOWN &&
 				 sym2->type != S_BOOLEAN &&
 				 sym2->type != S_TRISTATE)
 				prop_warn(prop,
 				    "'%s' has wrong type. '%s' only "
-				    "accept arguments of boolean and "
+				    "accept arguments of bool and "
 				    "tristate type", sym2->name, use);
 			break;
 		case P_RANGE:
@@ -298,6 +308,11 @@ void menu_finalize(struct menu *parent)
 
 	sym = parent->sym;
 	if (parent->list) {
+		/*
+		 * This menu node has children. We (recursively) process them
+		 * and propagate parent dependencies before moving on.
+		 */
+
 		if (sym && sym_is_choice(sym)) {
 			if (sym->type == S_UNKNOWN) {
 				/* find the first choice value to find out choice type */
@@ -315,30 +330,83 @@ void menu_finalize(struct menu *parent)
 				if (menu->sym && menu->sym->type == S_UNKNOWN)
 					menu_set_type(sym->type);
 			}
+
+			/*
+			 * Use the choice itself as the parent dependency of
+			 * the contained items. This turns the mode of the
+			 * choice into an upper bound on the visibility of the
+			 * choice value symbols.
+			 */
 			parentdep = expr_alloc_symbol(sym);
 		} else if (parent->prompt)
+			/* Menu node for 'menu' */
 			parentdep = parent->prompt->visible.expr;
 		else
+			/* Menu node for 'if' */
 			parentdep = parent->dep;
 
+		/* For each child menu node... */
 		for (menu = parent->list; menu; menu = menu->next) {
-			basedep = expr_transform(menu->dep);
+			/*
+			 * Propagate parent dependencies to the child menu
+			 * node, also rewriting and simplifying expressions
+			 */
+			basedep = rewrite_m(menu->dep);
+			basedep = expr_transform(basedep);
 			basedep = expr_alloc_and(expr_copy(parentdep), basedep);
 			basedep = expr_eliminate_dups(basedep);
 			menu->dep = basedep;
+
 			if (menu->sym)
+				/*
+				 * Note: For symbols, all prompts are included
+				 * too in the symbol's own property list
+				 */
 				prop = menu->sym->prop;
 			else
+				/*
+				 * For non-symbol menu nodes, we just need to
+				 * handle the prompt
+				 */
 				prop = menu->prompt;
+
+			/* For each property... */
 			for (; prop; prop = prop->next) {
 				if (prop->menu != menu)
+					/*
+					 * Two possibilities:
+					 *
+					 * 1. The property lacks dependencies
+					 *    and so isn't location-specific,
+					 *    e.g. an 'option'
+					 *
+					 * 2. The property belongs to a symbol
+					 *    defined in multiple locations and
+					 *    is from some other location. It
+					 *    will be handled there in that
+					 *    case.
+					 *
+					 * Skip the property.
+					 */
 					continue;
-				dep = expr_transform(prop->visible.expr);
+
+				/*
+				 * Propagate parent dependencies to the
+				 * property's condition, rewriting and
+				 * simplifying expressions at the same time
+				 */
+				dep = rewrite_m(prop->visible.expr);
+				dep = expr_transform(dep);
 				dep = expr_alloc_and(expr_copy(basedep), dep);
 				dep = expr_eliminate_dups(dep);
 				if (menu->sym && menu->sym->type != S_TRISTATE)
 					dep = expr_trans_bool(dep);
 				prop->visible.expr = dep;
+
+				/*
+				 * Handle selects and implies, which modify the
+				 * dependencies of the selected/implied symbol
+				 */
 				if (prop->type == P_SELECT) {
 					struct symbol *es = prop_get_symbol(prop);
 					es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr,
@@ -350,34 +418,81 @@ void menu_finalize(struct menu *parent)
 				}
 			}
 		}
+
+		if (sym && sym_is_choice(sym))
+			expr_free(parentdep);
+
+		/*
+		 * Recursively process children in the same fashion before
+		 * moving on
+		 */
 		for (menu = parent->list; menu; menu = menu->next)
 			menu_finalize(menu);
 	} else if (sym) {
+		/*
+		 * Automatic submenu creation. If sym is a symbol and A, B, C,
+		 * ... are consecutive items (symbols, menus, ifs, etc.) that
+		 * all depend on sym, then the following menu structure is
+		 * created:
+		 *
+		 *	sym
+		 *	 +-A
+		 *	 +-B
+		 *	 +-C
+		 *	 ...
+		 *
+		 * This also works recursively, giving the following structure
+		 * if A is a symbol and B depends on A:
+		 *
+		 *	sym
+		 *	 +-A
+		 *	 | +-B
+		 *	 +-C
+		 *	 ...
+		 */
+
 		basedep = parent->prompt ? parent->prompt->visible.expr : NULL;
 		basedep = expr_trans_compare(basedep, E_UNEQUAL, &symbol_no);
 		basedep = expr_eliminate_dups(expr_transform(basedep));
+
+		/* Examine consecutive elements after sym */
 		last_menu = NULL;
 		for (menu = parent->next; menu; menu = menu->next) {
 			dep = menu->prompt ? menu->prompt->visible.expr : menu->dep;
 			if (!expr_contains_symbol(dep, sym))
+				/* No dependency, quit */
 				break;
 			if (expr_depends_symbol(dep, sym))
+				/* Absolute dependency, put in submenu */
 				goto next;
+
+			/*
+			 * Also consider it a dependency on sym if our
+			 * dependencies contain sym and are a "superset" of
+			 * sym's dependencies, e.g. '(sym || Q) && R' when sym
+			 * depends on R.
+			 *
+			 * Note that 'R' might be from an enclosing menu or if,
+			 * making this a more common case than it might seem.
+			 */
 			dep = expr_trans_compare(dep, E_UNEQUAL, &symbol_no);
 			dep = expr_eliminate_dups(expr_transform(dep));
 			dep2 = expr_copy(basedep);
 			expr_eliminate_eq(&dep, &dep2);
 			expr_free(dep);
 			if (!expr_is_yes(dep2)) {
+				/* Not superset, quit */
 				expr_free(dep2);
 				break;
 			}
+			/* Superset, put in submenu */
 			expr_free(dep2);
 		next:
 			menu_finalize(menu);
 			menu->parent = parent;
 			last_menu = menu;
 		}
+		expr_free(basedep);
 		if (last_menu) {
 			parent->list = parent->next;
 			parent->next = last_menu->next;
@@ -426,6 +541,35 @@ void menu_finalize(struct menu *parent)
 			*ep = expr_alloc_one(E_LIST, NULL);
 			(*ep)->right.sym = menu->sym;
 		}
+
+		/*
+		 * This code serves two purposes:
+		 *
+		 * (1) Flattening 'if' blocks, which do not specify a submenu
+		 *     and only add dependencies.
+		 *
+		 *     (Automatic submenu creation might still create a submenu
+		 *     from an 'if' before this code runs.)
+		 *
+		 * (2) "Undoing" any automatic submenus created earlier below
+		 *     promptless symbols.
+		 *
+		 * Before:
+		 *
+		 *	A
+		 *	if ... (or promptless symbol)
+		 *	 +-B
+		 *	 +-C
+		 *	D
+		 *
+		 * After:
+		 *
+		 *	A
+		 *	if ... (or promptless symbol)
+		 *	B
+		 *	C
+		 *	D
+		 */
 		if (menu->list && (!menu->prompt || !menu->prompt->text)) {
 			for (last_menu = menu->list; ; last_menu = last_menu->next) {
 				last_menu->parent = parent;
@@ -450,6 +594,15 @@ void menu_finalize(struct menu *parent)
 		sym->flags |= SYMBOL_WARNED;
 	}
 
+	/*
+	 * For non-optional choices, add a reverse dependency (corresponding to
+	 * a select) of '<visibility> && m'. This prevents the user from
+	 * setting the choice mode to 'n' when the choice is visible.
+	 *
+	 * This would also work for non-choice symbols, but only non-optional
+	 * choices clear SYMBOL_OPTIONAL as of writing. Choices are implemented
+	 * as a type of symbol.
+	 */
 	if (sym && !sym_is_optional(sym) && parent->prompt) {
 		sym->rev_dep.expr = expr_alloc_or(sym->rev_dep.expr,
 				expr_alloc_and(parent->prompt->visible.expr,
@@ -682,14 +835,14 @@ static void get_symbol_str(struct gstr *r, struct symbol *sym,
 	get_symbol_props_str(r, sym, P_SELECT, _("  Selects: "));
 	if (sym->rev_dep.expr) {
 		str_append(r, _("  Selected by: "));
-		expr_gstr_print(sym->rev_dep.expr, r);
+		expr_gstr_print_revdep(sym->rev_dep.expr, r);
 		str_append(r, "\n");
 	}
 
 	get_symbol_props_str(r, sym, P_IMPLY, _("  Implies: "));
 	if (sym->implied.expr) {
 		str_append(r, _("  Implied by: "));
-		expr_gstr_print(sym->implied.expr, r);
+		expr_gstr_print_revdep(sym->implied.expr, r);
 		str_append(r, "\n");
 	}